(1) Field of the Invention
The present invention relates to a continuous drive ratchet tool designed for use in turning threaded fasteners. In particular, the invention relates to a tool that is adapted to be used to turn a threaded fastener in a first direction by connecting the tool to the fastener and rotating the tool in the first direction, and to override its connection to the threaded fastener allowing the fastener to remain stationary when rotating the tool in a second direction opposite the first direction, with there being no lost motion between the threaded fastener and the tool when rotating the tool to again turn the fastener in the first direction.
(2) Description of the Related Art
Conventional overriding ratchet wrenches of the type provided by the present invention commonly comprise a drive disk assembly received in a ratchet wrench housing. The disk drive assembly is designed to selectively rotate a bolt or nut threaded fastener in a first direction by attaching a socket to the drive disk and then connecting the socket to the fastener and rotating the ratchet wrench in the first direction. The drive disk is also designed to remain stationary and override relative to the ratchet wrench housing when the wrench is rotated in a second direction opposite to the first.
The housing of a conventional ratchet wrench is commonly provided with an opening at one end, and a handle extending from the opening to the second end of the wrench. The opening is completely surrounded by a series of ratchet teeth, and the drive disk is received in the opening.
The drive disk of a conventional ratchet wrench is commonly provided with a cylinder shaped body with a rectangular post projecting from one end of the body. A detent is commonly provided on one side of the post. The post is inserted into an opening at one end of a conventional ratchet wrench socket dimensioned to receive the post, to attach the socket in driving engagement with the drive disk. The detent at the side of the post provides a releaseable means of connecting the ratchet wrench socket on the post. A spring biased pawl mechanism is pivotally mounted in the drive disk, and opposite ends of the pawl selectively project from a cylindrical sidewall of the drive disk. The spring biased pawl is commonly provided with an engagement tooth at its opposite ends. The pawl is adjusted by a manual adjustment lever provided on the wrench to cause one of the two engagement teeth at the opposite ends of the pawl to engage behind one of the ratchet teeth provided on the interior surface of the opening in the ratchet wrench housing. By selectively engaging either of the pawl teeth behind a ratchet tooth of the ratchet wrench housing, the pawl is adjusted to enable relative rotation between the drive disk and the ratchet housing in a first direction of rotation while preventing relative rotation between the disk and housing in a second direction of rotation, or to enable relative rotation between the drive disk and ratchet housing in the second direction of rotation while preventing relative rotation between the disk and housing in the first direction of rotation. The pawl is spring biased to engage between adjacent ratchet teeth of the ratchet housing to prevent the rotation of the drive disk relative to the housing when the housing is rotated in one direction, and to overcome the spring bias and cam over consecutive ratchet teeth when the ratchet housing is rotated in a second direction relative to the drive disk.
The manner of using a conventional ratchet wrench is well known in the art. In use, a selected ratchet wrench socket is first mounted on the post of the drive disk of the wrench. The socket is then placed over the threaded fastener to be turned by the wrench. With the socket and ratchet wrench connected to the threaded fastener, the operator may then rotate the wrench in the desired direction to turn the fastener.
The primary beneficial feature of the conventional ratchet wrench is that it enables the user to rotate the threaded fastener by rotating the wrench in a first direction through a predetermined arch segment, and then to rotate the wrench in the opposite direction back through that arc segment while the fastener remains stationary, to reposition the ratchet wrench to again turn the threaded fastener in the first direction. This enables the user of the ratchet wrench to incrementally turn the threaded fastener in the first direction without removing the wrench from its driving connection to the fastener, where conventional open ended or box end wrenches must be removed from the fastener and then repositioned on the fastener repeatedly when making incremental turns of the fastener.
A common disadvantage found in conventional ratchet wrenches of the type described above, is that the wrench must be turned t advance the threaded fastener through at least a minimum arc length. This enables the wrench to then be turned in the opposite direction through the minimum arc length, and cause the pawl tooth engaging between adjacent ratchet teeth of the wrench housing to ride up and completely pass over at least one ratchet tooth and engage between the next two adjacent ratchet teeth to again establish a driving connection between the drive disk and the ratchet wrench housing. As a result of this construction, the wrenches can only be used where there is sufficient clearance to enable the rotation of the wrench through the minimum arc length required to cause the pawl tooth to completely pass over at least one ratchet tooth when the wrench is rotated back after advancing the fastener.
An additional limitation often encountered in using the conventional ratchet wrench is that by connecting a ratchet wrench socket to the ratchet wrench, the wrench can only be connected in driving engagement with a threaded fastener having sufficient clearance above the fastener to permit passage of the wrench and the attached socket over and onto the fastener. If the threaded fastener is located in a confined area with insufficient room above the fastener to insert the wrench and attached socket over and onto the fastener, a ratchet wrench cannot be used to turn the fastener and a conventional open ended or box end wrench must be used.
A further disadvantage often encountered in the use of conventional ratchet wrenches is that the length of the wrench handle often prevents the use of the wrench in confined working areas. In order to use a conventional ratchet wrench to turn a threaded fastener, there must be sufficient clearance around the threaded fastener to rotate the wrench handle through the minimum arc needed to reverse the wrench rotation at the end of the driving turn and cause the wrench pawl to completely pass over one of the ratchet teeth of the wrench.
A still further disadvantage found in using conventional ratchet wrenches is that the ratchet teeth or engagement teeth at the ends of the pawl have been known to break when the wrench is used to exert a large torque on a threaded fastener.
The present invention overcomes the disadvantages of prior art ratchet wrenches discussed above by providing a continuous drive ratchet tool apparatus that is not limited in its use by a minimum arc length through which the apparatus must be rotated in order to incrementally advance a threaded fastener.
It is also an object of the present invention to provide a continuous drive ratchet tool apparatus that comprises a driving disk that is completely contained inside the housing of the apparatus to reduce its width, with a socket extending into the disk that is dimensioned to receive the head of a threaded bolt or a threaded nut.
It is a further object of the present invention to provide a series of drive disks, each provided with a socket being dimensioned to receive a different sized head of a threaded bolt or a threaded nut, enabling the apparatus to be used to turn a variety of different size fasteners.
It is a still further object of the present invention to provide a continuous drive ratchet tool apparatus including a set of replaceable handles, the handles having different dimensions to enable the ratchet tool apparatus to be used in a variety of different situations, and including a handle that adapts the apparatus to be used as a torque wrench.
It is a still further object of the present invention to provide a continuous drive ratchet tool apparatus that does not employ ratchet teeth or a pivoting pawl that are capable of breaking at high torque loads, enabling the apparatus to exert a greater torque on threaded fasteners than is possible with a conventional ratchet wrench.